package learn.emp02.ex23;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int m = sc.nextInt();
        int s = sc.nextInt();
        int d = sc.nextInt();
        double h = (m*60+s)/3600.0;
        double miles = d/1.6;
        System.out.printf("%.2f",miles/h);
    }
}
